If you practice on Everdrive X7 and use Nudua's savestate patcher then only the US/EU version is supported and not the JP version. So I manually patched the J version to do the same thing so you can use quick savestates with that version on Everdrive.

Instructions: Patch with your favorite IPS patcher, for example Lunar IPS. After it's patched, put the rom and GBCSYS folder in the root of your SD card (or manually copy the SRM file into GBCSYS/SAVE)

Config: Select + Down = Save state Select + Up = Load state

Enjoy!